Composition for preventing of slime and method for preventing slime

ABSTRACT

A composition for preventing formation of slime which comprises a chlorine-based oxidizing agent, a sulfamic acid compound, one of an anionic polymer or a phosphonic acid compound and a process for preventing formation of slime which comprises adding the composition to a water system are disclosed. Troubles caused by slime in cooling water systems, heat-storage water systems, water systems in manufacturing processes of paper and pulp, water systems for collecting dusts and scrubber water systems can be effectively prevented with the composition in a small amount.

TECHNICAL FIELD

The present invention relates to a composition for preventing formationof slime and a process for preventing formation of slime. Moreparticularly, the present invention relates to a composition foreffectively preventing troubles caused by slime in cooling watersystems, heat-storage water systems, water systems in manufacturingprocesses of paper and pulp, water systems for collecting dusts andscrubber water systems in a small amount and a process using thecomposition.

BACKGROUND ART

Water is highly utilized in cooling water systems, water systems inmanufacturing processes of paper and pulp, water systems for collectingdusts and scrubber water systems due to insufficient water resources.For example, the amount of forced blow is decreased in the highlyconcentrated operation of open circulation cooling water systems. Whenwater is highly utilized as shown in the above example, the quality ofwater is lowered due to concentration of dissolved salts and nutrientsand slime is formed from a mixture containing microorganisms such asbacteria, fungi and algae, sand and dusts. When slime is formed, theheat efficiency in heat exchangers decreases and the flow of water issuppressed. Local corrosion of instruments and pipings takes place atportions covered with the attached slime.

To prevent troubles caused by slime such as those described above,utilization of various antimicrobial agents has been proposed. Forexample, in Japanese Patent Application Publication No. Showa41(1966)-15116, as the process for suppressing growth of microorganismsin the flow of treated water, a process which comprises mixing asolution of a salt of hypochlorous acid and a solution of a salt ofsulfamic acid to react these compounds and form a solution of a reactionproduct comprising a salt of N-chlorosulfamic acid, and supplying theformed solution into an aqueous flow for treatment, is disclosed. Ashigher utilization of cooling water further proceeds, the troublescaused by slime also increase further and it is required that anantimicrobial agent be added in a higher concentration. However, when anoxidative antimicrobial agent is used, it is difficult that theconcentration of the added agent is increased since the possibility ofcorrosion of metals increases. Moreover, since the oxidativeantimicrobial agent exhibits poor penetration into slime although theoxidizing ability is great, it is difficult that the troubles caused byslime are suppressed once the troubles take place.

In Japanese Patent Application Laid-Open No. Heisei 7(1995)-206609,taurine chloramine and others are proposed as novel bactericidescontaining a compound having halogen and nitrogen as the effectivecomponent. Since organic bactericides have a small or no oxidizingability and exhibit strong penetration into slime, it is possible thatthe troubles caused by slime are suppressed when the troubles takeplace. However, the spectrum of the effectiveness for the constitutingelements of the slime such as bacteria, fungi and algae is different foreach selected agent. Moreover, the cost of the agent is far greater thanthe oxidative antimicrobial agents and the cost of the treatmentmarkedly increases.

Therefore, an agent and a process for preventing formation of slimewhich are effective for all constituting elements of slime such asbacteria, fungi and algae with a small amount of the agent even underthe condition of severe troubles caused by slime and can preventformation of slime at a low cost, have been desired.

DISCLOSURE OF THE INVENTION

The present invention has an object of providing a composition and aprocess for effectively preventing troubles caused by slime by using asmall amount of the composition in cooling water systems, heat-storagewater systems, water systems in manufacturing processes of paper andpulp, water systems for collecting dusts and scrubber water systems.

As the result of intensive studies by the present inventors to overcomethe above problem, it was found that a chlorine-based oxidizing agentwas kept stable in a composition which comprised the chlorine-basedoxidizing agent, a sulfamic acid compound, and one of an anionic polymeror a phosphonic acid compound, and an excellent effect of preventingformation of slime was exhibited to the constituting elements of theslime such as bacteria, fungi and algae. The present invention has beencompleted based on this knowledge.

The present invention provides:

-   (1) A composition for preventing formation of slime which comprises    a chlorine-based oxidizing agent, a sulfamic acid compound and a    compound selected from an anionic polymer and a phosphonic acid    compound;-   (2) A composition for preventing formation of slime according to    (1), wherein the anionic polymer has a weight-average molecular    weight in the range of 500 to 50,000;-   (3) A composition for preventing formation of slime according to    (1), wherein said composition has a pH of 12 or greater, the    composition comprizing (a) sodium hypochlorite having a    concentration of effective chlorine of 1 to 8% by weight, (b) 1.5 to    9% by weight of sulfamic acid, (c) 2.5 to 20% by weight of sodium    hydroxide and (d) at least one of the anionic polymer, the solid    concentration of which is 0.5 to 4% by weight or at least one of the    phosphonic acid compound, the solid concentration of which is 0.5 to    4% by weight; each of the concentrations expressed in percentage    being calculated based on the total amount by weight of the    composition;-   (4) A composition for preventing formation of slime according to    (1), wherein said composition comprises:

component A, which comprises the chlorine-based oxidizing agent and hasa pH of 12 or greater, said component A comprising (a) sodiumhypochlorite having a concentration of effective chlorine of 1 to 8% byweight, (b) 1.5 to 9% by weight of sulfamic acid, (c) 2.5 to 20% byweight of sodium hydroxide, each of afore-said concentrations expressedin percentage being calculated based on the total amount by weight ofcomponent A; and

component B, which comprises (d) at least one of the anionic polymer,the solid concentration of which is 10 to 60% by weight or at least oneof the phosphonic acid compound, the solid concentration of which is 10to 60% by weight, each of afore-said concentrations expressed inpercentage being calculated based on the total amount by weight ofcomponent B;

-   (5) A composition for preventing formation of slime according to    (3), wherein the anionic polymer has a weight-average molecular    weight in the range of 500 to 50,000 and said anionic polymer is at    least one compound selected from the group consisting of polymaleic    acid, polyacrylic acid, a copolymer of acrylic acid and    2-hydroxy-3-allyloxypropane sulfonic acid, a copolymer of acrylic    acid and 2-acrylamide-2-methylpropane sulfonic-acid, a copolymer of    acrylic acid and isoprene sulfonic acid, a copolymer of acrylic acid    and 2-hydroxyethyl methacrylate, a copolymer of acrylic acid,    2-hydroxyethyl methacrylate and isopropylene sulfonic acid, a    coplolymer of maleic acid and pentene, a copolymer of maleic acid    and isobutylene, alkalin metal salts of afore-said anionic polymers    and an alkaline earth metal salts of afore-said anionic polymers;-   (6) A composition for preventing formation of slime according to    (1), wherein the chlorine-based oxidizing agent is at least one    compound selected from the group consisting of chlorine, alkali    metal hypochlorites, alkali metal chlorites and alkali metal    chlorates;-   (7) A composition for preventing formation of slime according to    (1), wherein the sulfamic compound is at least one compound selected    from the group consisting of sulfamic acid, N-methylsulfamic acid,    N,N-dimethylsulfamic acid, N-phenylsulfamic acid, alkali metal salts    of afore-said sulfamic acids, alkaline earth metal salts of    afore-said sulfamic acids and ammonium salts of afore-said sulfamic    acids,;-   (8) A composition for preventing formation of slime according to    (1), wherein the phosphonic acid compound is at least one compound    selected from the group consisting of    1-hydroxyethylidene-1,1,-diphosphonic acid,    2-phosphonobutane-1,2,4-tricarboxylic acid, hydroxyphosphonoacetic    acid, nitrilotrimethylene-phosphonic acid,    ethylenediamine-N,N,N′,N′-tetramethylene-phosphonic acid, alkali    metal salts of afore-said phosphonic acids, and alkaline metal salts    of afore-said phosphonic acids;-   (9) A process for preventing formation of slime in a water system,    the process comprising adding a composition for preventing formation    of slime which comprises a chlorine-based oxidizing agent, a    sulfamic acid compound and a compound selected from an anionic    polymer and a phosphonic acid compound to said water system;-   (10) A process for preventing formation of slime according to (9),    wherein the composition for preventing formation of slime has a pH    of 12 or greater and comprises (a) sodium hypochlorite having a    concentration of effective chlorine of 1 to 8% by weight, (b) 1.5 to    9% by weight of sulfamic acid, (c) 2.5 to 20% by weight of sodium    hydroxide and (d) at least one of the anionic polymer, the solid    concentration of which is 0.5 to 4% by weight or at least one of the    phosphonic acid compound, the solid concentration of which is 0.5 to    4% by weight; each of the concentrations expressed in percentage    being calculated based on the total amount by weight of said    composition;-   (11) A process for preventing formation of slime according to (9),    wherein the composition for preventing formation of slime comprises:

component A, which comprises the chlorine-based oxidizing agent and hasa pH of 12 or greater, said component A comprising (a) sodiumhypochlorite having a concentration of effective chlorine of 1 to 8% byweight, (b) 1.5 to 9% by weight of sulfamic acid, (c) 2.5 to 20% byweight of sodium hydroxide, each of afore-said concentrations expressedin percentage being calculated based on the total amount by weight ofcomponent A; and

component B, which comprises (d) at least one of the anionic polymer,the solid concentration of which is 10 to 60% by weight or at least oneof the phosphonic acid compound, the solid concentration of which is 10to 60% by weight, each of afore-said concentrations expressed inpercentage being calculated based on the total amount by weight ofcomponent B; and

-   (12) A process for preventing formation of slime according to (9),    wherein the water system is any one of cooling water system,    heat-storage water system, water system in manufacturing processes    of paper and pulp, water system for collecting dusts or scrubber    water systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a diagram exhibiting the apparatus used in Examples andComparative Examples.

The numbers in FIG. 1 has the following meanings.

-   -   1: A water tank    -   2: A circulation pump    -   3: A column    -   4: A tank for storing an agent    -   5: A pump for an agent    -   6: A valve

THE MOST PREFERRED EMBODIMENT TO CARRY OUT THE INVENTION

The composition for preventing formation of slime comprises achlorine-based oxidizing agent, a sulfamic acid compound and a compoundselected from an anionic polymer and a phosphonic acid compound. Theprocess for preventing formation of slime comprises adding achlorine-based oxidizing agent, a sulfamic acid compound and a compoundselected from an anionic polymer and a phosphonic acid compound to awater system.

Examples of the chlorine-based oxidizing agent used in the presentinvention include chlorine; alkali metal hypochlorites such as sodiumhypochlorite, potassium hypochlorite, alkaline earth metal hypochloritessuch as calcium hypochlorite and barium hypochlorite; alkali metalchlorites such as sodium chlorite, potassium chlorite, alkaline earthmetal chlorites such as barium chlorite and other metal chlorites suchas-nickel chlorite; and chlorates such as ammonium chlorate, alkalimetal chlorates such as_sodium chlorate potassium chlorate, and alkalineearth metal chlorates such as calcium chlorate and barium chlorate. Thechlorine-based oxidizing agent may be used singly or in combination oftwo or more. Among the above agents, hypochlorites are preferable due toeasiness in handling.

The sulfamic acid compound used in the present invention is a compoundrepresented by the following general formula [1]:

or the salt thereof.

In general formula [1], R¹ and R² represent hydrogen atom or ahydrocarbon group having 1 to 8 carbon atoms. Examples of the sulfamicacid compound represented by the general formula [1] include sulfamicacid in which R¹ and R² in the formula both represent hydrogen atom,N-methylsulfamic acid, N,N-dimethylsulfamic acid and N-phenylsulfamicacid. Examples of the salt of sulfamic acid compound used in the presentinvention include the alkali metal salt such as the sodium salt and thepotassium salt, akaline earth metal salt such as the calcium salt, thestrontium salt, the barium salt and the manganese salt, and other metalsalts such as the copper salt, the zinc salt, the iron salt, the cobaltsalt, the nickel salt, the ammonium salt and the guanidine salt.

It is preferable that the anionic polymer used in the present inventionhas a weight-average molecular weight in the range of 500 to 50,000,more preferably in the range of 1,000 to 30,000 and most preferably inthe range of 1,500 to 20,000.

Examples of the monomer providing the anionic polymer used in thepresent invention include unsaturated carboxylic acids such as acrylicacid, methacrylic acid and maleic acid; salts of the unsaturatedcarboxylic acids such as alkali metal salts including the sodium saltand the potassium salt or the alkaline earth metal salts including thecalcium salt and magnesium salt; and anhydrides of unsaturatedcarboxylic acids such as maleic anhydride. These monomers may be usedfor homopolymerization, copolymerization of two or more orcopolymerization of one or more with one or more other copolymerizablemonomers. Examples of the other copolymerizable monomer includeunsaturated alcohols, esters of unsaturated carboxylic acids, alkenesand monomers having sulfonic acid group. Examples of the unsaturatedalcohol include allyl alcohol and methallyl alcohol. Examples of theester of an unsaturated carboxylic acid include methyl acrylate, ethylacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate. Examplesof the alkene include isobutylene, n-butylene, diusobutylene andpentene. Examples of the monomer having sulfonic acid group includevinylsulfonic acid, 2-hydroxy-3-allyloxy-1-propanesulfonic acid,isoprenesulfonic acid and styrenesulfonic acid. Examples of the anionicpolymer used in the present invention include polymaleic acid,polyacrylic acid, a copolymer of acrylic acid and2-hydroxy-3-allyloxypropane sulfonic acid, a copolymer of acrylic acidand 2-acrylamide-2-methylpropane sulfonic acid, a copolymer of acrylicacid and isoprene sulfonic acid, a copolymer of acrylic acid and2-hydroxyethyl methacrylate, a copolymer of acrylic acid, 2-hydroxyethylmethacrylate and isopropylene sulfonic acid, a coplolymer of maleic acidand pentene, a copolymer of maleic acid and isobutylene, alkalin metalsalts of afore-said anionic polymers and an alkaline earth metal saltsof afore-said anionic polymers. The concentration of the anionic polymerin the water is 1 mg/L or more preferably 3 mg/L or more as solidcontent. Examples of the phosphonic acid compound used in the presentinvention include 1-hydroxyethylidene-1,1-diphosphonic acid,2-phosphonobutane-1,2,4-tricarboxylic acid, hydroxyphosphonoacetic acid,nitrilotrimethylene-phosphonic acid andethylenediamine-N,N,N′,N′-tetramethylene-phosphonic acid or the salts ofafore-said acids. Examples of the salt of the phosphonic acid includealkali metal salts such as the lithium salt, the sodium salt and thepotassium salt; and alkaline earth metal salts such as the magnesiumsalt and the calcium salt. The salt of the phosphonic acid may be anortho-salt in which hydrogen atoms as the characteristic components ofthe acid are completely substituted or an acidic salt in which some ofthe hydrogen atoms as the components of the acid remain. The phosphonicacid and the salt of the phosphonic acid may be used singly or incombination of two or more. The concentration of phosphonic acidcompound in the water is 1 mg/L or more preferably 3 mg/L as solidcontent.

The form of the composition for preventing formation of slime is notparticularly limited and may be, for example, a one-part agentcomprising all of the chlorine-based oxidizing agent, one of thesulfamic acid compounds and a compound selected from one of the anionicpolymer and one of the phosphonic acid compounds; or a two-part agentcomposed of two comprising the components. Examples of the two-partagent include an agent which comprises A-part comprising thechlorine-based oxidizing agent and the sulfamic acid compound and B-partcomprising the anionic polymer or the phosphonic acid compound.

When the agent is a one-part agent, it is preferable that pH is adjustedat 12 or greater and more preferably at 13 or greater by adding analkali such as sodium hydroxide and potassium hydroxide so thatstability of the chlorine-based oxidizing agent is maintained. When theagent is a two-part agent, it is preferable that pH of the partcomprising the chlorine-based oxidizing agent is adjusted at 12 orgreater and more preferably at 13 or greater due to the same reason.

In an embodiment of the one-part agent of the composition for preventingformation of slime, the composition has a pH of 12 or more and comprizes(a) sodium hypochlorite having a concentration of effective chlorine of1 to 8% by weight preferably 3 to 6% by weight, (b) 1.5 to 9% by weightpreferably 4.5 to 7% by weight of sulfamic acid, (c) 2.5 to 20% byweight preferably 7.5 to 15% by weight of sodium hydroxide and (d) atleast one of the anionic polymer, the solid concentration of which is0.5 to 4% by weight preferably 1.5 to 3% by weight or at least one ofthe phosphonic acid compound, the solid concentration of which is 0.5 to4% by weight preferably 1.5 to 3% by weight; each of the concentrationsexpressed in percentage being calculated based on the total amount byweight of the composition. In an embodiment of the two-part agent of thecomposition for preventing formation of slime, the composition comprisescomponent A, which comprises the chlorine-based oxidizing agent and hasa pH of 12 or greater, said component A comprising (a) sodiumhypochlorite having a concentration of effective chlorine of 1 to 8% byweight preferably 3 to 6% by weight, (b) 1.5 to 9% by weight preferably4.5 to 9% by weight of sulfamic acid, (c) 2.5 to 20% by weightpreferably 7.5 to 15% by weight of sodium hydroxide, each of afore-saidconcentrations expressed in percentage being calculated based on thetotal amount by weight of component A; and component B, which comprises(d) at least one of the anionic polymer, the solid concentration ofwhich is 10 to 60% by weight or at least one of the phosphonic acidcompound, the solid concentration of which is 10 to 60% by weight, eachof afore-said concentrations expressed in percentage being calculatedbased on the total amount by weight of component B.

When the composition and the process for preventing formation of slimeof the present invention are used, the excellent effects of preventingattachment of slime and preventing accumulation of sludge can beexhibited even when the composition is used in a small amount such thatthe antimicrobial effect is not obtained. When pasteurization ordisinfection is the object of the treatment as in the conventionalprocess, an agent must be added in a great concentration. Slime is dirtcontaining a mixture of flocks of microorganisms and inorganicsubstances such as sand and dust attached to pipings and heat transferpipes of heat exchangers. Sludge is dirt containing a mixture of flocksof microorganisms and inorganic substances such as sand and dustsaccumulated at the bottom of water tanks and separating plates of heatexchangers. The attachment of slime and the accumulation of sludge areconsidered to take place as follows. Growth and aggregation of inorganicparticles such as scales, sands, dusts and products of corrosion andgrowth and aggregation of microorganisms proceed simultaneously and thesize of minute floating substances gradually increases. Inorganicparticles are occluded into viscous substances formed by microorganisms,i.e., the so-called bioflocculation takes place, and the attachment ofslime and the accumulation of sludge take place. When the compositionand the process for preventing formation of slime of the presentinvention are used, it is considered that a synergistic effect isexhibited by the components for suppressing the bioflocculation and thecomponents exhibiting the effects of dispersing inorganic substances andsealing inorganic substance by the chelating effect, and the attachmentof slime and the accumulation of sludge can be effectively prevented.The composition and the process for preventing formation of slime of thepresent invention can be used advantageously in cooling water systems,water systems in manufacturing processes of paper and pulp, watersystems for collecting dusts and scrubber water systems.

EXAMPLES

The present invention will be described more specifically with referenceto examples in the following. However, the present invention is notlimited to the examples.

FIG. 1 shows a diagram exhibiting the apparatus used in Examples andComparative Examples. From a water tank 1 holding 15 liters of water,test water was passed at a rate of 10 liters/minute through a column 3and returned to the water tank 1 using a circulating pump 2. In thecolumn 3, a test board made of a synthetic rubber and having a surfacearea of 40 cm² was disposed to a supporting pole to measure the amountof attachment of slime.

In a water tank 4, test liquid for supplement prepared in advance wasstored and transferred into the water tank 1 at a rate of 5 ml/minuteusing a pump for an agent 5. The test liquid for supplement was preparedby adding calcium chloride and sodium hydrogencarbonate to city water,which was dechlorinated by passing through a column of active carbon, inamounts such that the calcium hardness was 150 mg CaCO₃/liter and theacid consumption (pH 4.8) was 150 mg CaCO₃/liter. As the nutrient formicroorganisms, 100 mg/liter of citric acid was added. To the obtainedsolution, a test agent was added and pH was adjusted at 8.5 by addingsodium hydroxide.

When the test was started, dirt was added into the water in the watertank 1 in an amount such that the turbidity of the water was 50. As thedirt, a concentrated liquid of reverse washing discharged from filtersfor industrial water in Chiba area was used. The dirt was added into thewater tank 1 in an amount corresponding to a turbidity of 25 at eachtime when 48 hours and 96 hours had passed after the start of the test.

The number of microorganisms in the circulating water and the turbidityof the circulating water were measured 48 hours, 72 hours and 120 hoursafter the start of the test. The test board of synthetic rubber attachedto the column 3 was taken out 120 hours after the start of the test.After slime attached to the test board was cleaved and dried to theconstant weight at 105° C., the weight of the slime was measured and theamount of the attached slime was obtained.

A valve 6 at a lower portion of the water tank 1 was opened and thewater in the water tank 1 was removed 120 hours after the start of thetest. The valve 6 was then closed again. Into the water tank 1, 200 mlof pure water was added and dirt accumulated at the lower portion of thewater tank was suspended using a brush. The valve was opened and theformed suspension was taken out. After the dirt was separated using acentrifuge and dried to the constant weight at 105° C., the weight ofthe dirt was measured and the amount of accumulated sludge was obtained.

As part A of the test agent, a mixed liquid composed of 40% by weight ofan aqueous solution of sodium hypochlorite having a concentration ofeffective chlorine of 12% by weight, 8% by weight of a sulfamic acid,10% by weight of sodium hydroxide and 42% by weight of water was used.This mixed liquid is a solution conventionally used as the agent forpreventing formation of slime. As part B of the agent, an anionicpolymer or a phosphonic acid was used.

Comparative Example 1

In place of the test liquid for supplement, water for supplementprepared as follows was used. To city water dechlorinated by passingthrough a layer of active carbon, calcium chloride and calciumhydrogencarbonate were added in an amount such that the calcium hardnesswas 150 mg CaCO₃/liter and the acid consumption (pH 4.8) was 150 mgCaCO₃/liter; 100 mg/liter of citric acid was added as the nutrient formicroorganisms; and pH of the prepared water was adjusted at 8.5 byadding sodium hydroxide. The test was conducted for 120 hours.

The number of microorganisms in the circulating water was 1.7×10⁵ after48 hours, 1.2×10⁵ after 72 hours and 1.3×10⁵ after 120 hours. Theturbidity of the circulating water was 3.5 after 48 hours, 2.1 after 72hours and 2.8 after 120 hours. The amount of attached slime was 20.0mg/dm² and the amount of accumulated sludge was 94.4 mg after 120 hours.

Example 1

To the test liquid for supplement, part A of the test agent in an amountsuch that the concentration of effective chlorine was 5 mg/liter andpolymaleic acid [manufactured by GREAT LAKES CHEMICAL Company; BELCLENE;the weight-average-molecular weight: 2,730] in an amount such that theconcentration of solid components was 5 mg/liter as part B of the testagent were added and the test was conducted for 120 hours.

The number of microorganisms in the circulating water was 2.8×10⁶ after48 hours, 2.4×10⁷ after 72 hours and 3.2×10⁷ after 120 hours. Theturbidity of the circulating water was 9.5 after 48 hours, 10.2 after,72 hours and 12.2 after 120 hours. The amount of attached slime was 1.0mg/dm², the fraction of preventing attachment of slime was 95.0%, theamount of accumulated sludge was 5.2 mg and the fraction of preventingaccumulation of sludge was 94.5% after 120 hours.

Example 2

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that a maleic acid-isobutylene copolymer[manufactured by KURARAY Co., Ltd.; ISOBAN; the weight-average molecularweight: 10,800] was used as component B in place of polymaleic acid.

Example 3

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that an acrylicacid-hydroxyallyloxypropanesulfonic acid copolymer [manufactured byNIPPON SHOKUBAI Co., Ltd.; AQUARICK GL; the weight-average molecularweight: 10,700] was used as component B in place of polymaleic acid.

Example 4

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that 1-hydroxyethylidene-1,1-diphosphonicacid [manufactured by MONSANTO Company; DEQUEST 2010] was used ascomponent B in place of polymaleic acid.

Example 5

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that 2-phosphonobutane-1,2,4-tricarboxylicacid [manufactured by BAYER Company; BAYHIBIT AM] was used as componentB in place of polymaleic acid.

Example 6

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that hydroxyphosphonoacetic acid[manufactured by GREAT LAKES Company; BELCORE 575] was used as componentB in place of polymaleic acid.

Comparative Example 2

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that part A of the test agent alone wasadded to the test liquid for supplement in an amount such that theconcentration of effective chlorine was 5 mg/liter.

The number of microorganisms in the circulating water was 1.4×10⁵ after48 hours, 2.2×106 after 72 hours and 2.8×10⁶ after 120 hours. Theturbidity of the circulating water was 5.7 after 48 hours, 5.4 after 72hours and 5.7 after 120 hours. The amount of attached slime was 8.7mg/dm², the fraction of preventing attachment of slime was 56.5%, theamount of accumulated sludge was 35.5 mg and the fraction of preventingaccumulation of sludge was 62.4% after 120 hours.

Comparative Example 3

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 2 except that part A was added in anamount such that the concentration of effective chlorine was 10mg/liter.

Comparative Example 4

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that a maleic acid-isobutylene copolymer[manufactured by KURARAY Co., Ltd.; ISOBAN] alone was added to the testliquid for supplement as part B of the test agent in an amount such thatthe concentration of solid components was 5 mg/liter.

Comparative Example 5

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 4 except that a maleic acid-isobutylenecopolymer [manufactured by KURARAY Co., Ltd.; ISOBAN] was added in anamount such that the concentration of solid components was 10 mg/liter.

Comparative Example 6

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that an acrylicacid-hydroxyallyloxy-propanesulfonic acid copolymer [manufactured byNIPPON SHOKUBAI Co., Ltd.; AQUARICK GL] alone was added to the testliquid for supplement as part B of the test agent in an amount such thatthe concentration of solid components was 5 mg/liter.

Comparative Example 7

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 6 except that the acrylicacid-hydroxyallyloxypropanesulfonic acid copolymer [manufactured byNIPPON SHOKUBAI Co., Ltd.; AQUARICK GL] was added in an amount such thatthe concentration of solid components was 10 mg/liter.

Comparative Example 8

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that 1-hydroxyethylidene-1,1-diphosphonicacid [manufactured by MONSANTO Company; DEQUEST 2010] alone was added tothe test liquid for supplement as part B of the test agent in an amountsuch that the concentration of solid components was 5 mg/liter.

Comparative Example 9

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 8 except that1-hydroxyethylidene-1,1-diphosphonic acid [manufactured by MONSANTOCompany; DEQUEST 2010] was added in an amount such that theconcentration of solid components was 10 mg/liter.

Comparative Example 10

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that 2-phosphonobutane-1,2,4-tricarboxylicacid [manufactured by BAYER Company; BAYHIBIT AM] alone was added to thetest liquid for supplement as part B of the test agent in an amount suchthat the concentration of solid components was 5 mg/liter.

Comparative Example 11

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 10 except that2-phosphonobutane-1,2,4-tricarboxylic acid [manufactured by BAYERCompany; BAYHIBIT AM] was added in an amount such that the concentrationof solid components was 10 mg/liter.

Comparative Example 12

The test was conducted in accordance with the same procedures as thoseconducted in Example 1 except that hydroxyphosphonoacetic acid[manufactured by GREAT LAKES Company; BELCORE 575] alone was added tothe test liquid for supplement as part B of the test agent in an amountsuch that the concentration of solid components was 5 mg/liter.

Comparative Example 13

The test was conducted in accordance with the same procedures as thoseconducted in Comparative Example 12 except that hydroxy-phosphonoaceticacid [manufactured by GREAT LAKES Company; BELCORE 575] was added in anamount such that the concentration of solid components was 10 mg/liter.

The results of the measurements of the attachment of slime and theaccumulation of sludge in Examples 1 to 6 and Comparative Examples 1 to13 are shown in Table 1. The numbers of microorganisms in thecirculating water are shown in Table 2 and the turbidities of thecirculating water are shown in Table 3. TABLE 1 Part B concn. AttachmentAccumulation Part A of solid of slime of sludge (effective componentsamount fraction of fraction of chlorine) (mg/ (mg/ prevention amountprevention (mg/liter) type liter) dm²⁾ (%) (mg) (%) Comparative — — —20.0 — 94.4 — Example 1 Example 1 5 polymaleic acid 5 1.0 95.0 5.2 94.5Example 2 5 maleic 5 1.6 92.0 6.5 93.1 acid-isobutylene copolymerExample 3 5 acrylic acid-hydroxy- 5 1.8 91.0 7.2 92.4allyloxypropanesulfonic acid copolymer Example 4 5 1-hydroxyethylidene-5 1.7 91.5 5.5 94.2 1,1-diphosphonic acid Example 5 5 2-phosphonobutane-5 2.0 90.0 6.8 92.8 1,2,4-tricarboxylic acid Example 6 5hydroxyphosphono- 5 1.9 90.5 7.6 92.0 acetic acid Comparative 5 — — 8.756.5 35.5 62.4 Example 2 Comparative 10 — — 4.2 79.0 18.2 80.7 Example 3Comparative — maleic 5 19.0 5.0 60.3 36.1 Example 4 acid-isobutylenecopolymer Comparative — maleic 10 16.5 17.5 48.7 48.4 Example 5acid-isobutylene copolymer Comparative — acrylic acid-hydroxy- 5 18.48.0 65.5 30.5 Example 6 allyloxypropanesulfonic acid copolymerComparative — acrylic acid-hydroxy- 10 17.7 11.5 40.3 57.3 Example 7allyloxypropanesulfonic acid copolymer Comparative —1-hydroxyethylidene- 5 17.3 13.5 42.8 54.7 Example 8 1,1-diphosphonicacid Comparative — 1-hydroxyethylidene- 10 16.1 19.5 39.6 58.1 Example 91,1-diphosphonic acid Comparative — 2-phosphonobutane- 5 19.2 4.0 55.541.2 Example 10 1,2,4-tricarboxylic acid Comparative —2-phosphonobutane- 10 16.5 17.5 48.8 48.3 Example 11 1,2,4-tricarboxylicacid Comparative — hydroxyphosphono- 5 18.7 6.5 57.6 39.0 Example 12acetic acid Comparative — hydroxyphosphono- 10 16.5 4.0 51.1 45.9Example 13 acetic acid

TABLE 2 Part B concn. Part A of solid Number of microorganisms(effective components in circulating water (/ml) chlorine) (mg/ afterafter after (mg/liter) type liter) 48 hours 72 hours 120 hoursComparative — — — 1.7 × 10⁵ 1.2 × 10⁵ 1.3 × 10⁵ Example 1 Example 1 5polymaleic acid 5 2.8 × 10⁶ 2.4 × 10⁷ 3.2 × 10⁷ Example 2 5 maleic 5 7.5× 10⁵ 4.2 × 10⁶ 4.8 × 10⁶ acid-isobutylene copolymer Example 3 5 acrylicacid-hydroxy- 5 3.7 × 10⁶ 4.8 × 10⁶ 6.2 × 10⁶ allyloxypropanesulfonicacid copolymer Example 4 5 1-hydroxyethylidene- 5 3.3 × 10⁶ 3.2 × 10⁶4.2 × 10⁶ 1,1-diphosphonic acid Example 5 5 2-phosphonobutane- 5 4.3 ×10⁶ 2.9 × 10⁶ 3.2 × 10⁶ 1,2,4-tricarboxylic acid Example 6 5hydroxyphosphono- 5 4.7 × 10⁶ 2.6 × 10⁶ 2.8 × 10⁶ acetic acidComparative 5 — — 1.4 × 10⁵ 2.2 × 10⁶ 2.8 × 10⁶ Example 2 Comparative 10— — 4.3 × 10⁵ 7.4 × 10⁶ 7.2 × 10⁶ Example 3 Comparative — maleic 5 2.9 ×10⁵ 3.5 × 10⁵ 3.8 × 10⁵ Example 4 acid-isobutylene copolymer Comparative— maleic 10 3.4 × 10⁵ 3.9 × 10⁵ 7.2 × 10⁵ Example 5 acid-isobutylenecopolymer Comparative — acrylic acid-hydroxy- 5 7.2 × 10⁵ 3.6 × 10⁵ 4.2× 10⁵ Example 6 allyloxypropanesulfonic acid copolymer Comparative —acrylic acid-hydroxy- 10 6.6 × 10⁵ 4.6 × 10⁵ 3.8 × 10⁵ Example 7allyloxypropanesulfonic acid copolymer Comparative —1-hydroxyethylidene- 5 7.2 × 10⁵ 5.5 × 10⁵ 4.9 × 10⁵ Example 81,1-diphosphonic acid Comparative — 1-hydroxyethylidene- 10 1.3 × 10⁶4.9 × 10⁵ 6.8 × 10⁵ Example 9 1,1-diphosphonic acid Comparative —2-phosphonobutane- 5 6.7 × 10⁵ 8.4 × 10⁵ 4.2 × 10⁵ Example 101,2,4-tricarboxylic acid Comparative — 2-phosphonobutane- 10 3.8 × 10⁶8.9 × 10⁵ 7.6 × 10⁵ Example 11 1,2,4-tricarboxylic acid Comparative —hydroxyphosphono- 5 4.8 × 10⁵ 5.5 × 10⁵ 7.2 × 10⁵ Example 12 acetic acidComparative — hydroxyphosphono- 10 6.6 × 10⁵ 3.5 × 10⁵ 4.9 × 10⁵ Example13 acetic acid

TABLE 3 Part B concn. Part A of solid Turbidity of (effective componentscirculating water (degree) chlorine) (mg/ after after after (mg/liter)type liter) 48 hours 72 hours 120 hours Comparative — — — 3.5 2.1 2.8Example 1 Example 1 5 polymaleic acid 5 9.5 10.2 12.2 Example 2 5 maleic5 8.6 7.7 15.2 acid-isobutylene copolymer Example 3 5 acrylicacid-hydroxy- 5 8.8 11.2 14.4 allyloxypropanesulfonic acid copolymerExample 4 5 1-hydroxyethylidene- 5 9.1 9.3 11.8 1,1-diphosphonic acidExample 5 5 2-phosphonobutane- 5 8.3 9.5 14.3 1,2,4-tricarboxylic acidExample 6 5 hydroxyphosphono- 5 8.0 8.5 10.9 acetic acid Comparative 5 —— 5.7 5.4 5.7 Example 2 Comparative 10 — — 5.5 5.7 9.7 Example 3Comparative — maleic 5 3.9 3.6 3.9 Example 4 acid-isobutylene copolymerComparative — maleic 10 4.2 4.5 3.6 Example 5 acid-isobutylene copolymerComparative — acrylic acid-hydroxy- 5 3.8 3.5 4.2 Example 6allyloxypropanesulfonic acid copolymer Comparative — acrylicacid-hydroxy- 10 4.1 4.1 3.8 Example 7 allyloxypropanesulfonic acidcopolymer Comparative — 1-hydroxyethylidene- 5 3.7 3.6 3.9 Example 81,1-diphosphonic acid Comparative — 1-hydroxyethylidene- 10 3.7 3.9 4.5Example 9 1,1-diphosphonic acid Comparative — 2-phosphonobutane- 5 3.94.1 4.6 Example 10 1,2,4-tricarboxylic acid Comparative —2-phosphonobutane- 10 4.3 3.8 4.2 Example 11 1,2,4-tricarboxylic acidComparative — hydroxyphosphono- 5 4.1 4.5 4.1 Example 12 acetic acidComparative — hydroxyphosphono- 10 4.3 4.7 4.5 Example 13 acetic acid

As shown in Table 1, when the results in Examples 1 to 6, in which partA comprising sodium hypochlorite and sulfamic acid in amounts such thatthe concentration of effective chlorine was 5 mg/liter and part Bcomprising the anionic polymer or the phosphonic acid in an amount suchthat the concentration of solid components was 5 mg/liter were used incombination, were compared with the results in Comparative Example 1 inwhich no agent for preventing formation of slime was added, in Examples1 to 6, the amount of attachment of slime and the amount of accumulationof sludge were both smaller than on tenth of those in ComparativeExamples and the fraction of preventing attachment of slime and thefraction of preventing accumulation of sludge both exceeded 90%. Asshown in Table 2, in Examples 1 to 6, the effect of preventingattachment of slime and the effect of preventing accumulation of sludgewere exhibited even when the number of microorganisms in the circulatingwater was relatively great and the concentration of the agent forpreventing formation of slime was not in the range exhibiting themicrobicidal effect. As shown in Table 3, in Examples 1 to 6, theflocculation of suspended substances did not take place and theattachment as slime or the accumulation as sludge could be preventedeven when the turbidity of the circulating water was relatively greatand the suspended substances were present in the circulating water in arelatively great amount.

In Comparative Example 2 in which part A was added in an amount suchthat the concentration of effective chlorine was 5 mg/liter withoutadding part B, the fraction of preventing attachment of slime and thefraction of preventing accumulation of sludge were both about 60%. Evenwhen the amount of part A was increased to 10 mg/liter in ComparativeExample 3, the fraction of preventing attachment of slime and thefraction of preventing accumulation of sludge were both about 80%. Thus,it is shown that the combined use of part A and part B in Examples 1 to6 exhibited the synergistic effect. In Comparative Examples 2 and 3, thesmaller turbidity of the circulating water than that in Examples 1 to 6show that the amount of the suspended substances remaining in the waterwas smaller and the amount of the suspended substances which wasflocculated and attached as slime and accumulated as sludge was greater.

In Comparative Examples 4 to 13 in which part B comprising the anionicpolymer or the phosphonic acid alone was added in an amount such thatthe concentration of solid components was 5 mg/liter or 10 mg/literwithout adding part A, the fraction of preventing attachment of slimeand the fraction of preventing accumulation of sludge were both small.Thus, it is shown that the combined use of part A and part B in Examples1 to 6 exhibited the synergistic effect. In Comparative Examples 4 to13, the effect of preventing accumulation of sludge is poorer than theeffect of preventing attachment of slime. In Comparative Examples 4 to13, the turbidity of the circulating water was smaller than that inExamples 1 to 6 and Comparative Examples 2 and 3 and it is shown thatthe amount of suspended substances remaining in the water was smaller.

As shown in Table 2, the number of microorganisms in the circulatingwater in Comparative Example 1 was not substantially different fromthose in circulating water in Comparative Examples 2, 4 and 8 and it isshown that the microbicidal effect is not exhibited when part A alonewas added in an amount such that the concentration of effective chlorinewas 5 mg/liter or part B alone was added in an amount such that theconcentration of solid components was 5 mg/liter. The fact that, inaccordance with the present invention, the excellent effects ofpreventing attachment of slime and accumulation of sludge were exhibitedat a small concentration such that the effective microbicidal effectcould not be obtained in accordance with conventional technology showsthat the formation of viscous substances by microorganisms andbioflocculation by the modifying activity could be prevented even whenthe microbicidal effect was not exhibited. It is also considered thatthe synergistic effect could be obtained by the dispersion effect andthe combined use of the component having the sealing property.

Example 7

A composition composed of 40% by weight of an aqueous solution of sodiumhypochlorite having a concentration of effective chlorine of 12% byweight, 8% by weight of sulfamic acid, 10% by weight of an anionicpolymer or a phosphonic acid and the remaining amount of sodiumhydroxide and water was prepared. pH of the composition was adjusted bychanging the amount of sodium hydroxide. The prepared composition wasstored in a vessel kept at the constant temperature of 40° C. andshielded from light. The concentration of the effective chlorine wasmeasured after the composition was stored for a prescribed time.

For the measurement of the concentration of the effective chlorine, aresidual chlorine meter manufactured by HACH Company and a reagentspecific for this measurement were used. BELCREN (the weight-averagemolecular weight: 2730) manufactured by GREAT LAKES CHEMICAL Company wasused as the polymaleic acid. ISOBAN (the weight-average molecularweight: 10,800) manufactured by KURARAY Co., Ltd. was used as the maleicacid-isobutylene copolymer. AQUARICK GL (the weight-average molecularweight: 10,700) manufactured by NIPPON SHOKUBAI Co., Ltd. was used asthe acrylic acid-hydroxyallyloxypropanesulfonic acid copolymer. DEQUEST2010 manufactured by MONSANTO Company was used as1-hydroxyethylidene-1,1-diphosphonic acid. BAYHIBIT AM manufactured byBAYER Company was used as 2-phosphonobutane-1,2,4-tricarboxylic acid.BELCORE 575 manufactured by GREAT LAKES Company was used ashydroxyphosphonoacetic acid.

The results are shown in Table 4. In the aqueous solution of sodiumhypochlorite, the concentration of effective chlorine remained only byabout 60% after one month and about 20% after 3 month at pH 14. Incontrast, the compositions prepared above showed excellent stabilitywhen pH had great values. It was confirmed that the effective chlorineremained after 3 months by as much as 50% or more at pH 12 and 90% ormore at pH 13 or greater. It was also confirmed that the compositionswere very unstable at pH 11. As shown above, the stability of the agentcomprising the chlorine-based microbicidal agent, sulfamic acid compoundor a salt thereof and a compound selected from an anionic polymer, aphosphonic acid and a salt of a phosphonic acid depends on pH and veryexcellent stability can be obtained at pH 12 or greater. TABLE 4Fraction of remaining effective chlorine (%) pH of after after afterComposition composition 7 days 30 days 90 days Aqueous solution ofsodium 14 91 59 18 hypochlorite alone Sodium hypochlorite + sulfamicacid + 14 100 100 99 sodium hydroxide 13 100 100 99 12 99 97 89 11 90 6325 Sodium hypochlorite + sulfamic acid + 14 100 99 98 sodium hydroxide +polymaleic acid 13 97 97 94 12 96 91 75 11 76 33 5 Sodium hypochlorite +sulfamic acid + 14 100 99 99 sodium hydroxide + maleic acid-isobutylenecopolymer 13 100 99 98 12 99 95 86 11 83 45 8 Sodium hypochlorite +sulfamic acid + 14 98 99 96 sodium hydroxide + acrylic acid- 13 98 94 90hydroxyallyloxypropanesulfonic acid copolymer 12 86 50 15 11 51 4 1Sodium hypochlorite + sulfamic acid + 14 100 95 90 sodium hydroxide +1-hydroxyethylidene-1,1-diphosphonic 13 98 83 61 acid 12 90 78 50 11 558 0 Sodium hypochlorite + sulfamic acid + 14 100 100 99 sodiumhydroxide + 2-phosponobutane-1,2,4-tricarboxylic 13 100 100 99 acid 1299 96 87 11 85 45 8 Sodium hypochlorite + sulfamic acid + 14 100 100 99sodium hydroxide + hydroxyphosphonoacetic acid 13 99 99 97 12 99 94 8311 62 10 2

INDUSTRIAL APPLICABILITY

In accordance with the composition and the process for preventingformation of slime of the present invention, attachment of slime topipings, heat exchangers and various instruments can be prevented andaccumulation of sludge in water tanks and separating plates in heatexchangers can also be effectively prevented by adding the compositionin a small amount such that no microbicidal effects are exhibited. Asthe result, it is made possible that troubles caused by attachment ofslime and accumulation of sludge in various water systems are preventedand the cost required for cleaning can be remarkably decreased.

1. A composition for preventing formation of slime which comprises achlorine-based oxidizing agent, a sulfamic acid compound and a compoundselected from an anionic polymer and a phosphonic acid compound.
 2. Acomposition for preventing formation of slime according to claim 1,wherein the anionic polymer has a weight-average molecular weight in therange of 500 to 50,000.
 3. A composition for preventing formation ofslime according to claim 1, wherein said composition has a pH of 12 orgreater, the composition comprizing (a) sodium hypochlorite having aconcentration of effective chlorine of 1 to 8% by weight, (b) 1.5 to 9%by weight of sulfamic acid, (c) 2.5 to 20% by weight of sodium hydroxideand (d) at least one of the anionic polymer, the solid concentration ofwhich is 0.5 to 4% by weight or at least one of the phosphonic acidcompound, the solid concentration of which is 0.5 to 4% by weight; eachof the concentrations expressed in percentage being calculated based onthe total amount by weight of the composition.
 4. A composition forpreventing formation of slime according to claim 1, wherein saidcomposition comprises: component A, which comprises the chlorine-basedoxidizing agent and has a pH of 12 or greater, said component Acomprising (a) sodium hypochlorite having a concentration of effectivechlorine of 1 to 8% by weight, (b) 1.5 to 9% by weight of sulfamic acid,(c) 2.5 to 20% by weight of sodium hydroxide, each of afore-saidconcentrations expressed in percentage being calculated based on thetotal amount by weight of component A; and component B, which comprises(d) at least one of the anionic polymer, the solid concentration ofwhich is 10 to 60% by weight or at least one of the phosphonic acidcompound, the solid concentration of which is 10 to 60% by weight, eachof afore-said concentrations expressed in percentage being calculatedbased on the total amount by weight of component B.
 5. A composition forpreventing formation of slime according to claim 3, wherein the anionicpolymer has a weight-average molecular weight in the range of 500 to50,000 and said anionic polymer is at least one compound selected fromthe group consisting of polymaleic acid, polyacrylic acid, a copolymerof acrylic acid and 2-hydroxy-3-allyloxypropane sulfonic acid, acopolymer of acrylic acid and 2-acrylamide-2-methylpropane sulfonicacid, a copolymer of acrylic acid and isoprene sulfonic acid, acopolymer of acrylic acid and 2-hydroxyethyl methacrylate, a copolymerof acrylic acid, 2-hydroxyethyl methacrylate and isopropylene sulfonicacid, a coplolymer of maleic acid and pentene, a copolymer of maleicacid and isobutylene, alkalin metal salts of afore-said anionic polymersand an alkaline earth metal salts of afore-said anionic polymers.
 6. Acomposition for preventing formation of slime according to claim 1,wherein the chlorine-based oxidizing agent is at least one compoundselected from the group consisting of chlorine, alkali metalhypochlorites, alkali metal chlorites and alkali metal chlorates.
 7. Acomposition for preventing formation of slime according to claim 1,wherein the sulfamic compound is at least one compound selected from thegroup consisting of sulfamic acid, N-methylsulfamic acid,N,N-dimethylsulfamic acid, N-phenylsulfamic acid, alkali metal salts ofafore-said sulfamic compounds, alkaline earth metal salts of afore-saidsulfamic compounds and ammonium salts of afore-said sulfamic compounds.8. A composition for preventing formation of slime according to claim 1,wherein the phosphonic acid compound is at least one compound selectedfrom the group consisting of 1-hydroxyethylidene-1,1-diphosphonic acid,2-phosphonobutane-1,2,4-tricarboxylic acid, hydroxyphosphonoacetic acid,nitrilotrimethylene-phosphonic acid,ethylenediamine-N,N,N′,N′-tetramethylene-phosphonic acid, alkali metalsalts of afore-said phosphonic acids, and alkaline metal salts ofafore-said phosphonic acids.
 9. A process for preventing formation ofslime in a water system, the process comprising adding a composition forpreventing formation of slime which comprises a chlorine-based oxidizingagent, a sulfamic acid compound and a compound selected from an anionicpolymer and a phosphonic acid compound to said water system.
 10. Aprocess for preventing formation of slime according to claim 9, whereinthe composition for preventing formation of slime has a pH of 12 orgreater and comprises (a) sodium hypochlorite having a concentration ofeffective chlorine of 1 to 8% by weight, (b) 1.5 to 9% by weight ofsulfamic acid, (c) 2.5 to 20% by weight of sodium hydroxide and (d) atleast one of the anionic polymer, the solid concentration of which is0.5 to 4% by weight or at least one of the phosphonic acid compound, thesolid concentration of which is 0.5 to 4% by weight; each of theconcentrations expressed in percentage being calculated based on thetotal amount by weight of said composition.
 11. A process for preventingformation of slime according to claim 9, wherein the composition forpreventing formation of slime comprises: component A, which comprisesthe chlorine-based oxidizing agent and has a pH of 12 or greater, saidcomponent A comprising (a) sodium hypochlorite having a concentration ofeffective chlorine of 1 to 8% by weight, (b) 1.5 to 9% by weight ofsulfamic acid, (c) 2.5 to 20% by weight of sodium hydroxide, each ofafore-said concentrations expressed in percentage being calculated basedon the total amount by weight of component A; and component B, whichcomprises (d) at least one of the anionic polymer, the solidconcentration of which is 10 to 60% by weight or at least one of thephosphonic acid compound, the solid concentration of which is 10 to 60%by weight, each of afore-said concentrations expressed in percentagebeing calculated based on the total amount by weight of component B. 12.A process for preventing formation of slime according to claim 9,wherein the water system is any one of cooling water system,heat-storage water system, water system in manufacturing processes ofpaper and pulp, water system for collecting dusts or scrubber watersystems.